minor improvements for text search (#2407)

Author: jeff-allen-mongo

source/includes/fact-text-index.rst

@@ -1,3 +1,6 @@
-MongoDB provides :ref:`text indexes <index-feature-text>` to support
-text search queries on string content. ``text`` indexes can include any
-field whose value is a string or an array of string elements.
+To run text search queries on self-managed deployments, you must have a
+:ref:`text index <index-feature-text>` on your collection. MongoDB
+provides text indexes to support text search queries on string content.
+Text indexes can include any field whose value is a string or an array
+of string elements. A collection can only have **one** text search
+index, but that index can cover multiple fields.

source/text-search.txt

@@ -47,8 +47,8 @@ string content. To perform text search, MongoDB uses a :ref:`text index
 
 To learn more about text search for self-managed deployments, see: 
 
-- :doc:`Text Indexes </core/link-text-indexes/>` 
-- :doc:`Text Search Operators </core/text-search-operators/>`
+- :ref:`text-search-on-premises` 
+- :ref:`text-search-operators-on-premises`
 
 MongoDB also supports text search for various languages. For a list of
 supported languages, see :ref:`text-search-languages`.